Pure Green 100% Natural Latex Mattress Topper - Firm - 3" King Size Latex Provides Amazing Pinpointed Support - Sleep Better Instantly 100% Natural Latex - No Synthetic Latex - No Fillers The extra-firm support of this topper is great anyone who enjoys a firm supportive mattress (Firmness rating is 44 ILD) 5.9 lbs/cubic ft Latex Foam Naturally Stays Cool 44 ILD (A Measurement of Firmness) 5.9 Lbs/ Cubic Ft (Density)